Plug for lug straps and method of making same



Sept, 22, 1931. J. H. CHADBOURNE ,7 I PLUG FOR LU G STQRAPS AND METHODOF K 1N6 SAIB Filed July 5. 1929 2 Sheets-Sheet 1 ALI 12:: enter;

p 1931- J. H. CHADBOURNE 1,824,707

PLUG FOR LUG STRAPS AND METHOD OF IAKING SAIE Filed July 5. 1929ZSheots-Sheet 2 Patented Se t; 22, 1931 UNITED STATES PATENT OFFICEJOSEPH H. CHL'DBOUBNE, *OF nnmnson', CONNEQTICUT, ASSIGNOR TO B. H.JACOBS MIG. 60,01 DANIELSON, CONNECTICUT, A CORPORATION OF CONNECTICUTrand non 1.1m s rens Am) mnrnon or MAKING smn Application'fil ed July 5,1929. Serial No. 375,930.

My present invention relates to lug straps plug for lug Lug straps forlooms are ordinarily made .of-fabric, such as ticking or canvas, rolledup after having glue or other adhesive applied'thereto and then moldedinto substan tially rectangular shape in cross section and after theglue has set the lug strap is formed into its final sha e, that is, itis given a final U shape. The nishing operations are then made,thereonand the lug strap is ready for market. Heretofore it has beenusual toform theplug as an integral part of the structure, whichnecessitated a plying auxiliary, or additional pieces of abric to thestrip of fabric above referred .to, making the finally formedrectangular member thicker at the middle than at the ends, so that whenthe lug strap was given its final form, the thickened middle portionbecame the plug or equivalent thereof. The bending operation resulted inforcing the fibres at the bend of the lug strap out of their initialposition, placing too great a strain on the other curve of the lug strapandnot enough strain on the inner curved portion. Also, it waszfoundthatthe inner curved portion separated a cbnsiderable distance CIH'Vfrom the-outer portion, with the result that the ln strap in use breaksaway at the outer I portion thereof, or the enlarged plug end tears awayfrom the structure.

It was endeavored to. correct thisylatter fault by passing a rivetthrough the enlarged end, but this expedient did not cor- I plug frombeing separated from. the'side rect the fault as the breakage thenoccurred at the rivet hole, although it did prevent the members of thelug strap.

In 'my present lnventi" n I have avoided the difliculties found in priorstructures and have devised an improved---plug-i;. for lug straps, whichis preformed and afterwards 4 added to the-lug strap structure. Thepreforming may take place in a varlety of ways,

' 'depending mainly on the type of lug strap it is desired 'to build,and numerous advan-1 straps and the method of maksing thesame.

tages result from the structure. The usual.

lug strap portion is built up in the usual way but without the additionof any reinforcing pieces to cause an enlargement at .the middle portionthereof, as in former construction. The result is, therefore, that onthe forming of the lug strap proper there is produced a substantiallyrectangular member uniform as regards width and thickness throughout itsentire length, which structure it has been found may be bent into a Ushape without any appreciable distortion of the fabric plies at the bentportion. I

The lug'strap' is preferably bent around an arbor havin a fixed contourso that the. inner end of t e lug strap is provided with a contour ofpredetermined shape. By preforming the plugs I am able to produce a lugstrap in which the plug fits snugly against the fabric of the inner faceof the U-shaped lug member and may be riveted in further that the pliesof fabric in the bent end of the lug strap are in close engagement witheach other and under practically equal tension that another life isimparted to. the lug strap.

In carrying out my invention I so arrange the plies of fabric as toprovide for the most economical use thereof and make,

therefore, an elongated member composed of a roll of fabric impregnatedwith adhesive and hardened and set and which may have a plurality ofplugs separated therefrom preferably by. sawing or cutting, andwhich'plugs have the final shape necessary and which may be inserted inposition in lug strap sides and ends with the assurance that the samewill fit and may be held in positioninl any suitablemanner as by rivets.

. The principal object of my invention, therefore, is an improved methodof manufacturing plugs for lug straps and the like.

Fig. 11

Another object of my invention is an improved plug for lug straps.

Referring to the drawings illustrating the process by which my improvedmethod may be practiced and the resulting product,

Fig. 1 shows an elongated roll of fabric and adhesive from which a blankcontainshape made in the press of Fig. 2 and with one of the plugsseparated therefrom;

Fig. 6 is a perspective view of the plug material as formed in the pressshown in Fig. 3, one of the plugs being shown sepa-' rated therefrom;

Fig. 7 is a perspective view of the plug material such as has beenformed in the press shown in Fig. 4, one of the plugsbeing separatedtherefrom;

Fig. 8 is a view of a plug as shown in Fig. 6 held in position in a lugstrap;

Fig. 9 is a side elevation of Fig. 8;

Fig. 10.is a section on the line 101O of Fig. 8;

Fig. 11 is a plan view of one end of a lug strap similar to the oneshown in Fig. 8 but fitted with a plug of the character shown in Fig. 5;

Fig. 12 is a section on the line 1212 of Fig. 13 is a section on theline 1313 of Fig. 12;

Fig. 14 is a plan view of a portion of a lug strap similar to that shownin Figs. 8 and 11 but fitted with a plug of the character shown in Fig.7, and i Fig. 15 is a section on the line 1515 of Fig. -14. 5

Referring to the drawings, 10 designates a layer of fabric, such asticking or canvas,

which has been impregnated with adhesive,

such for example as glue, and rolled into cylindrical form, asillustrated in Fig. 1.

While still in a moist condition such roll may be placed in a mold 11 ofa press, such. mold being provided with a substantially rectangularrecess and into which is fitted a slidably mounted plunger 12. By theuse of the rectangular recess in conjunction with the plunger 12 theroll illustrated in 1 is given a shape that is substantially rectangularin cross-section, as designated by the numeral 13 in Fig. 2, and themember 13 is held in position in the recess in the mold 11 until it hasbecome set or in the condition shown, for example, in Fig. 5. In placeof the mold 11 having a rectangular recess therein I may employ a mold14 provided with a recess designated to give to the roll composed of thefabric 10 a rounded shape on one end, as indicated by the numeral 15.With the mold 14 is employed a plunger 16, such plunger on its lowerface being provided with a plurality of grooves therein, each grooveforming in the roll, composed of the fabric 10, a plurality of raisedportions 17 these raised portions being on the member 27 formed in themold 14, as clearly shown in Fig. 6. In place of the mold 14 I mayemploy a similar mold 18 but utilize in connection therewith a plunger19 that has a rounded lower end so as to provide a groove 20 extendingalong {)he length of the member 21 formed there- In utilizing the member13 to form plugs for use in lug straps, one end is preferably rounded,as indicated at 22 and a saw or sha cutter is employed to cuttransversely o the member 14 at the appropriate point so as to separatetherefrom a plug 23 formed with one end 24 raised therefrom. I

Referring now to Figs. 8 to 15 inclusive, there is shown in such figures2. lug strap formed of a rectangular strip of fabric impregnated withglue and folded or formed into the -U shape, as shown in the figures,such U shape consisting of the side member 25 and a rounded end member26, the side members 25 being provided with elongated slots 28 throughwhich holding members may be passed. The plug 23 above described asbeing cut off from the plug member 13 is fitted into the spacebetween'the side plates 25 and end member 23, as clearly shown in Fig.11, and it will be noted that the contour of the rounded end 22 of suchplug 23 coincides with the curvature of the inner face of the roundedend 26. After being positioned, the side members 25 and plug member 23are drilled to receive a rivet 29,

a washer 30 being placed on the end there of and the end headed over, asindicated at 31, this structure firmly holding the plug 23 in positionon the lug strap members 25 and 26. .The close connection between therounded end portion 26 and the rounded portion 22 of the plug 23 isclearly shown in Fig. 12. Also, in this form of the improved plug itwill be noted that the rounded portion 24 consists of the plurality ofupstanding plies formed of the layer 10 of fabric and, therefore, that ablow imparted to such rounded end will have merely the effect ofspreading the plies outwardly but will not penetrate through such pliestransversely.

Referring to Figs. 8 and 9, there is shown therein a form of the plugillustrated in Fig. 6 and in this form, which is held in position in thesame manner as the form above degiven a predetermined shape corresscribed, the rounded end it is the opposite to that shown in Fig. '5,and blows imparted to the plug cut from the member 27 will tend to beexerted transversely of the fabric.

In the form of the invention illustrated in Figs. 14 and15, that form oflug cut from the member 31 shown in Fig. is shown in position.

In all forms of my device the with the curvature of the interior aces othe side members and end member of the lug strap illustrated in Figs. 8to 15 in, elusive and the holding of the same in position by riveting isfor positioning purposes only, as the rounded end of the lug strapclosely fitting with the inner curvature of the end member 26, any blowsimparted to the face of the plug will be absorbed by the entire end ofthe lug strap. Further,

the rounded end of the lug strap has the various elements thereof undersubstantial stress or strain and the breakage of lug straps at the endof the rounded portion has been eliminated.

Having thus described my invention, what I claim as new is:

That improvement in the art of forming plugs of condensed textile layersfor use in lug straps, which consists in utilizing a strip of textilematerial, havin a width equal to a predetermined plurahty of subsequentlug straps to be formed therefrom,

forming from said fabric sheet an elongated.

roll impregnated with adhesive, compressing said elongated roll intoacondensed bar having a length equal to said lugs to be formedtherefrom, dividing said bar into plug-sized sections by visible linesof division, and thereupon separating individual plugs from said bar onsaid lines of division. i

In testimony whereof, I have signed my name to this specification.

JOSEPH H. CHADBQURNE.

plurality of

